Hi there, I camp Grynas (Grynas Hill torch defense) and shouts for my guildies whenever it’s up. It seems that the silver is around 7k per drop, of which may or may not be scaled to level (I will test further with my alt who’s been moved there with my guild’s helpful guildmaster.)
Grynas Hill’s math thing also give Lightning Property Resist Potion, which gives Lightning resist of 30 for 1 minute. Not impressive, but this does mean it can drop a number of different elemental property resist potions. Possibly more.
In addition, you can do the arithmetic “piece” gathering in other areas - I had the Gimmick on me, and was surprised when I was getting some stuff elsewhere, and had the arithmetic piece info popped out. I went back to Grynas Hill, and it works just fine.